1. Field of the Invention
The invention relates to an inductive power coupling device for coupling electrical power between two units that are rotatable against each other, and, specifically for power couplers used in computed tomography scanners. Such power couplers are also known as rotary joints.
2. Description of Relevant Art
In computed tomography (CT) scanners and other related machines high-power in the range from 10 kW up to more than 100 kW is transferred from a stationary side to a rotating side. There, a high voltage in the range of above hundred kilovolts is generated to produce x-ray radiation.
In U.S. Pat. No. 7,054,411 a multiple channel inductive rotary joint is disclosed. It has inductive channels for transferring power from the stationary side to the rotating side. There is an auxiliary power and a main power circuit. Furthermore a capacitive feedback link for power control is provided. There may be some failure states such as a short circuit of a rotating power channel to protective earth, which may cause dangerous high voltages at the rotating part and which may cause the rotating part of the feedback link to be inoperative and, therefore, may interfere with the communication to a primary power controller.